Primary target platform is Linux on AMD64 (x86-64) with GCC or Clang compilers. This is what the developers use.
Secondary target platforms are macOS on x86-64 with Xcode (Clang compiler) and Windows on x86-64 with MSVC compiler. Bugs that affect these platforms will be treated as release blockers.
Tertiary target platforms are Linux on POWER8/POWER9 (both big- and little-endian: power64, ppc64, power64le, ppc64le), ARMv7 (armhf, armhfp), and ARMv8 (arm64, aarch64) with GCC or Clang and also other modern Unix-like operating systems and compilers. Bugs that affect these platforms will be fixed if feasible.
Quaternary targets are x86 and older POWER processors. Bugs that affect these platforms will be considered for fixing if a patch is provided.